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J. LOFGREN. COMBINATIUN SAFETY SWITCH AND RECEPTACLE. APPLICATION FILEDDEc.2s.191a.

Ill/111AA @www 1. I OFGREN.

CUMBINATION SAFETY SWITCH AND RECEPTACLE.

APPLICATION FILED DEC.26. I9I8.

Patented July 20, 1920.l

2 SHEETS-SHEET 2.

'for vestablishm UNITED STATES PATEVr ,oFFlcI-:Ql

JOHN LOFGREN, 0F CHICAGO, ILLINOIS, ASSIGNOR T0 RALCO MANUFACTURING C0.,

0F CHICAGO, ILLINOIS, A C

OBPORATION OF ILLINOI COMBINATION SAFETY SWITCH AND RECEPTACLE.

'Application mea December 2s, 191s.

To all whom timely concern: y

Bewitlmown that I, JOHN LoFGnEN, a citizen of the United States, residinat Chicago,in'the county of Cookand tate of Illinois, have invented 'acertain new and useful CombinationSafet Switch and Reg ceptacle,fofwhich the fol owing is laspeciiication. p

My invention is embodied in a combined switchand receptacle, the generalobject of which is tojprevent misoperationof the 'parts and topreventtheir operation in ,im

proper sequence.,` In installing electric translating devices,especially ,portable or removable ones, it is common practice to employa plug and' 'receptacle 4as a. connector electrical connection.between,A the trans ating device andthe supply conductors; Goodpractice demands thata service switch, be interposed f between theconnector and the leading-in wires;also thattheswitch should be open4whenever the plug is being inserted or Withdrawn from the receptacle. iBut users of translating devices are often careless or ignorant of thedemands ofy oodpractice and it is very common for t e operator towithdraw or insert the plug While the service switch is closed. Thisfrequently causes arcing, which endangers the apparatus and may eveninjure theoperator. One of the objects of my invention' is to make itimpossible for the operator to insert or withdraw the 'plug unless theswitch is open. Ordinarily the service switch is an independent piece ofapparatus from the receptacle and is some times installed at a distancefrom it. One of the contributory objects ofmy invention is to combinethem so that they may constitute a sin le piece ofapparatus. Safety isthe undeying purpose of the invention and in .order-to provide safety it.is one of the objects of the invention to inclose the switch within yabox and operate it from a point outside of the box. so that if there isany arcing it Will occur within the box and hence be relativelyharmless. With this in mind Iprovide a door for the box and providemechanism which. will hold the door closed until after the plug has beenwithdrawn, and the switch opened. Another ob Iiect is to provide meansby which the switch will be locked open so long as the door remainsopen. In the form selected to illustrate the invention the plug isinserted by Specification of Letters Patent.

my purpose to Patented July 20, 1920. Serial No. 268.311. i

this connection it is provide means for preventingthe reversal of theplug the purpose being to insure that the conr uctors in the cord orcable will always beconnected to thefproper respective supplyconductors. Anotherobject is to provide means whereby the plug will, ifonly partially insertedpr withdrawn from the receptacle, prevent theswitch from being closed.- Other contributorynbjects lwill becomeapparent ,as the descriptlon proceeds. q

In the accompan ingdrawingsf-A `i Figure`1 is `aontLelevationofnapparatus embodyingthe invention, the box-being shownvertical section 'and thel -plug and receptacle also being'shown chiefly,in vertical section.

Fig. 2 is a perspective view illustrating the cooperation ofconstituentparts ofthe device. i

Fig. 3 Vis a p1 an;secti0n showin theA receptacle and bracket and partso the receptacle. i

Fig. 4 is a side elevation of the complete apparatus, the box and itsdoor being in section. v l

Fig. 5 is similar to Fig. 4 except that the parts are shown in changedposition.

Like reference numerals denote like parts throughout the several views.

In the illustrated form of the invention there is a boiY 1 which isintended `to be mounted in fixed osition. It is with a doorA 2 in rontwhich is hinged at the upper end upon a pintle 3. A Vpanel 4 of slate orother insulating material is fastened at the back of the box forsupporting the service switch. This is illustrated as a single throw,three pole switch having three switch blades 6, 7 and .8 adapted toengage three stationary contacts 9, 10 and 11 respectively, to which arefastened three leading-in wires 12, 13, 14 respectively. It will beunderstood, however, that while I have illustrated a three wire systemthe same principle would apply to a system having more or less thanthree wires. The switch is operated by a handle 16 and the switch bladesor arms are pivoted to the terminals 17, 18, 19, thesefbeingelectrically connected to the conductors 20, 21 and 22, respectivelywhich lead to sockets 23, 24, 25, respectively, mounted in thereceptacle block 26. Block 26 consists of porcelain or a straight-inpush. In

provided 1iii) l receptacle,

other insulating material und is supported upon a bracket 27 within thebox. The precise form o the punts thus ar described is immaterial, themint boing thwt the switch is mounted within the box and connected tothe terminals .nifthe receptacle7 which is also carried by the box andpreferably with- :4 The plug consists'in the present case, of a block 3Hof porcelain cr other insulating material mounted within a shelll havinga clamp 32liy whiclfit may y=be coi'inected to 'flexible `conduit 3B;The conductors 34, 35,"36 whichare ihcased Within the sheath -of thecoinduit 33 are electrically connected 'to the pins 37, 38, 39respectively, which are adpted to lit-intothejsockets 2 3, 9A', 25,respectively1 ,to make electrical connections therewith. A 4^ v At thesidfof the shell 31 there'is ormed a `lug 40 A'which is adapted to pass.through the slot'4l orrned in thejbottornof the box. As this slot.affords the lonly entrance for the lug,Y itprevents the =plug rom beingini i butithie ii itonc to connect theproper conductors t Ae conduit tothe propei'pois oftht/ switch.' -:Hence it may'besaladier the plug withitsiqgj 4u is non-reversible. Y

Iriiiledu near he *bottoin ofl the 4box. is s. roclrsht 345'3operated'bya ha'ri'dlevcr I44 located outside of the boxes best showninFig.' 'IMstirieitothisA4 haft inside vof the boztls an iti-'in -l5 which`is bifu'rcfit'ed 'at the upper end to engage the switch handie 1G.Thusthels'vvitch inay point oiits'ideof the box by oper-"ating:r handle44. rI `he rock shaft also has an arm lffastened toit which carriesido'g 47 so placed as to move into and out of thepath ofthe lug?y 40 inharmony-` with'the movements of the rock shaft and switch. `Theconstruc- 1tionY is such that when the switch is closed -the dog willblock the path of the lug, preventing the plug,r bein'ginserted 'if outof the and preventing the plug being withdrawn if within the receptacle.If the 'plug is not pushed completel h'ome in -zhe recemment@ dogwin-stri, ze u1@ Side of the lu" )and preventthe switch from 'beingclose' Thus it 'will seen, 'thatj'the plug e'annotbe Withdrawn unlessthe switch -is open 'not' can it be inserted uhiess'th'e switch isopen', 'and the switch cannot'be 'closed unlessthep'lu'g is inserted `tothe full 'and :proper distance.'

Now, referring to the lockout, whereby the switch is prevented fromclosing when the plug i's not inV position in the receptacle; an arm 50is vpii'roted'to abracket'l' extending back of the box. his erm'v hs ashoulder 52 adapted, when lowerechto dro behind the rr'nglG and preventthe rock shaft from being rotated in a' Iii- 4motion to close theswitch.Y A lug 54 is "the door locked.v XYVhen be operated from a-"formed on the side of arm 50 in such inanner that when the plug is inposition in the receptacle the lug 40 will engageiiug-LM and holdthelockout firm 50 up in non-acting position, but when the plug iswithdrawn it will permit seid arm to drop. lf the switch operating armis in a position corresponding to the closed position of the switch theshoulder 52 will drop onto the upper endof a'rm '46 and be supported byit. lf, however, the arm 45 moves therswitch to open position the arm 4Gwil-lfp'ass to the front of shoulder 52, thus permittinfrhsaid shoulder'to drop behind arm 446 and lock the switch -open. Hence, the switchcannot be again closed until the ,plug has been re inserted andthe lug40 has engaged the lufT 54and raised the lockout arm high enougi topermit the arm 46 to clear the shoulder 52. y

The mechanism for holding the door locked includes ahook 5G adapted tobe en- .gaged by aheok 57 formed at the outer end 'of arm 50. When theplug is inposition "inthe receptacle it holds the :ir/m sufhhooli 56yand hold the vplugjs4 Withfar" @H011 h'lo Clear thehook 56 beforeftheshoulder 2bn "said armiwili contact theuppcr end o f'the arm cientlyelevateA to engage drawm' arm 50 will drop 4G. Thus the"withdrawai ofthelplug will unlock the door. l n

I haveprovided means' or requiring door .tobe closed before 4theswitchfcan lbe movedfrom open to yclosed position. n is mechanismincludes a latch 60', pivotedA-to the bracket 61, fastened `to the backof the box near the top. vSaid latchhas'y a shoulder GQ'adapted to dropbehindthehorizontal portion 63 of the arm 45 when the latter is movedforward far enough to open the switch. A bracket 64 is mounted on the4inside of the door near the hinge and' is ,so positioned that when thedoor is closed the bracket will hold the latch hi h enough to clear thehorizontal portion 6 of arm 45, and permit the switch to moveto closedposition. If thedoor vis opcn, 'hitch 62, will rest upon the horizontalportion 63 so 'that the moment it passes beyond shoulder 62. saidshoulder will drop back ofit ,and lock it in open position.

Operation: Let it be assumed that the parts are'hssemblcd as shown inEig's.-4 1 and 4,4 the switch being closed` the door closed and theplugr in position. The luge() holds lug 54 elevated so thatA ho'k 5'(will' engawe the hook 56 and hold the door locked. e dog 47 will alsoblock the path lof lug 54H and prevent the withdrawal o -the plug.

`Hence if itisdesired towithdrew the p'lug ble to withdraw the plug,whereupon the arm 5() will drop sullciently to cause the hook 57 todisengage the hook 56. Consequently, the door is now unlocked and may beopened. The lowering of arm 5() causes the shoulder 52 to drop back ofthe arm 46 and lock the switch open. Furthermore, the opening, of thedoor permits the shoulder 62 to drop behind the horizontal portion 63fof the arin45, sol that the switch will nowbe locked open by twoseparate and independent mechanisms. The advantage of the latch 6() isthat it prevents the plug from heilig inserted and the switchsubsequently closed while the door is open.- It compels the.attendant tooperate the parts in the proper sequence,-that is, to first close thedoor, then insert the plug, and then close the switch.

It will be noted that the latch 60 is up near the top of the box whereit is not readily accessible. The advantage of this arrangement is thatit makes it diiicult for the attendant to get at the latch todeliberately raise it while the door is open and thus'defeat the purposeof the latch.

It will be understood that the actual form of the parts may beconsiderably varied without departing from the spirit of the invention.It will al'so be understoodthat it is not essential that all of theelements of the device be present in order to produce an operative anduseful structure. For example, the door .locking mechanism may beomitted without destroying the cooperative effect of the lug 40 with thedog 47. Similarly, the latch 60 may be omitted without destroying theability of the coperating hooks 56, 57, to hold the door locked so longas the plug remains within the receptacle.

In the accompanying claims I do not wish to be understood as employingthe terms plug and receptacle in the unduly restricted sense that thereceptacle is the chambered part and that the plug has a portionentering into it. I employ the terms in the broader sense that thereceptacle is the stationary part and the plug the removable one.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent, is

l. Electric apparatus comprising a throw switch, a box inclosing saidswitch, a receptacle carried by said box, a plug for said receptacle,the receptacle having a longitudinal slot and the plug having a lugsliding in said slot whereby the plug is nonreversible, a dog adapted tomove into and out of the path of the lug for blocking its movement, ahandle for operating said dog, and means operated by said handle andadapted to coordinate the switch with the dog for moving the dog intoacting position when the switch is closed.

2. In a device of the class described, thc.` combination of a switchbox, a door for closing it, a receptacle carried by the box, a plug forthe receptacle, and locking means for holding the door closed. saidlocking means being held by the plug in acting position when the plug isin position within the receptacle. whereby the door cannot be openedwithout first withdrawing the plug.

3. In combination, a switch box, a door for it, a locking arm, adaptedwhen in raised position to engage the door for locking it, a receptacle,and a plug for the receptacle` said plug being adapted to hold thelocking arm raised in locking position, when the plug is in thereceptacle.

4. In a device of the class described, the combination of a switch, abox inclosing it, a door for the box, a receptacle carried by the box, aplug for the receptacle, and locking means for holding the door closed,said locking means being held in actin position when the plug is inposition in t e recep tacle, said locking means being adapted to unlockthe door when the plug is withdrawn and said locking means being alsoadapted when thus released by the plug to automatically engage theswitch and lock it 1n open position when said switch has been moved toopen position.

A combined switch and receptacle comprising a box, a switch mountedtherein, a door hinged to the box, a latch within the box adapted tohold the switch open, means operated by the door for lifting the latchwhen the door is closed and thus releasing the switch so that it may beclosed, a receptacle carried by the box, a plug for entering saidreceptacle, and a lockout adaptedto hold the switch in open position,said lockout being adapted to release the switch when the plug isinserted into the receptacle, whereby the door must be 'closed and theplug inserted before the switch can be closed.

6. A combined switch and receptacle comprising a box, a switch mountedtherein, a door hinged to the box, a latch Within the box adapted tohold the switch open, means op erated by the door for lifting the latchwhen the door is closed and thus releasing the switch so that it may beclosed, a receptacle carried by the box, a plugr for entering saidreceptacle, a lockout adapted to hold the switch in open position, saidlockout being adapted to release the switch when the plug is insertedinto the receptacle, whereby the door must be closed and the pluginserted before the switch can be closed, and a handle located outsidethe box, and having connections passing through the wall of the box andadapted to engage the switch to thereby enable the operator to close theswitch after the door has been closed and the plug inserted.

7. A combined switch and receptacle comwhereby the switeh must prising:i box, u switch mounted therein`r :L door for the box, :1, reccptuclocarried by the box, :L plug for enteringr Said receptacle, u door lookcontrolled by the plug and adopted to hold the door locked when the plugis inserted, a dog for preventingr the withdrawal of the plug, andIneens moving in harmony with the switch Jfor moving:4 the dogr to.nonaeting position us the switch moves open, be open before the plug can`be withdrawn and the door cannot -befopened until the plug iswithdrawn.

8. A combined switch und receptacle eemprising u box, it switch mountedtherein, u a door for the box, a receptacle carried by the box, a plugfor entering said receptaele u door lock controlled by the plu r andadapted to hold Athe door locked when t 1e plug is inserted, a dog forpreventing the withdrawal o'lI the plugyun :mn connected `to the :switchund moving in unison therewith for moving the dog to non-notin positionwhen the switch moves open, nn n handle located outside of the box undconnected to the switch for opening it.

9. In a device switch, u reeeptuele, mele, u box inclosing the of theclass described, at

:t plug for the recepswiteh, a handle Aoutside of the box'oonnected tothe switch for lclosing 1t, a, lug on the side of the plug, und

:in 'arm adapted to engage seid lug when the plug is in an intermediateposition in the receptacle to thereby prevent the bundle from closingthe switch.

In witness whereof' l have hereunto subscribed my name.

JoHN LoFGREN.

